Swash

Hello all, I’ve recently taken the plunge into concertinas with a Stagi Anglo I found on eBay. I’ve just received it and it appears to have some buttons stuck (see pics in link). This model doesn’t seem to be opened as easily as simply unscrewing and I’m looking for advice as to whether or not this is something I can repair on my own or should look to taking in to a shop. thanks in advance, I look forward to being a member of this community! -Corey pics: https://imgur.com/gallery/MGFL1MU